A color printer with an LED exposure system is known in the art as one type of electrophotographic color printer. This color printer is provided with four photosensitive drums corresponding to the colors yellow, magenta, cyan, and black, and four LED units for respectively exposing the photosensitive drums.
One such color printer that has been proposed includes a main casing, and a process cartridge that is detachably mounted in the casing. The process cartridge is provided with drum cartridges for retaining the photosensitive drums, and developer cartridges that are detachably mounted on the drum cartridges for retaining developing rollers. The printer also includes LED units for exposing the photosensitive drums. The process cartridge is mounted in and removed from the printer through an opening formed in the top surface of the main casing by opening a top cover provided thereon.